To distribute air in an HVAC system, an air distribution system, including air-handling units, move the air between the space to be ventilated and a plant. The air-handling units include fans for moving the air in zones, rooms, or other areas local to the occupant space.
The air handling is controlled by one or more controllers, such as controllers in a panel. Using a set of rules, the controller causes the air-handling units to provide more or less flow. For example, feedback from a temperature sensor is used to increase or decrease fan speed to drive the temperature to within a range of a set point. Due to poor design, wear, or other reasons, the air-handling unit may not operate optimally or may be incapable of sufficient operation. The rule-based control may not identify improper operation other through error reporting. For more complex air distribution systems with multiple interconnected air-handling units, the rule-based control may not deal with interactions between the air-handling units.